Buckle for safety belts



Dec. 8, 1964 G. Y. HOLMBERG 3,159,892

BUCKLE EOR SAFETY BELTS Filed Aug. 7, 1962 1 24 I 24 INVENTOR 23 I 11' '23 o'r ESKIL YNGVE HOLMBERG BY KARL b.) K004;

ATTORNEY United States Patent 3,159,892 BUCKLE FUR AFETY BELTS Giite Eslril Yngve Holmberg, Tokarp,

Anderstorp, Sweden Filed Aug. 7, 1962, Ser. No. 215,413 3 Claims. Il. 24-230) This invention relates to a buckle, particularly for safety belts, comprising a lock housing and a locking tongue insertable in said housing to a locking position therein, said lock housing and said locking tongue forming abutment surfaces arranged to prevent, by mutual engagement, withdrawal of the locking tongue from the locking position in the lock housing, a latch in the lock housing movable into and out of a latching position and adapted in latching position to coact with the lock housing to prevent the abutment surfaces from being moved out of mutual engagement by displacement of the locking tongue relative to the lock housing transversely of the direction of insertion/withdrawal, spring means for biasing the latch into latching position, and an operating member for moving the latch out of latching position against the action of the spring bias.

This type of buckle has found a wide use with safety belts for motor cars primarily because the latch and the operating member are not loaded by the pull to which the buckle may be exposed under load, for which reason the buckle is easily opened even under load. In the generally customary design of the buckle of the prior art the abutment surfaces are constituted by a pair of projections in the lock housing which are stamped in the material of the lock housing, and by a boundary surface of each of a pair of holes in the locking tongue which are adapted each to accommodate one of the projections. .This embodiment is excellent and serves its purpose well but it has.

been found that it is possible considerably to improve and simplify the buckle without losing therefore any of the advantagesassociated with the prior art buckle recited above.

To this end it is suggested according to the present invention to let the abutment surfaces in a buckle of the kind referred to be formed by an angularly bent end portion of the locking tongue and by a boundary surface of a slot formed by the lock housing, in which slot the angularly bent end portion of the locking tongue is insertable. The primary gain of this arrangement is that the buckle can be made shorter since the material which in the customary embodiment lies between the projections and a slot for fastening the strap of the belt connected to the lock housing, is dispensed with entirely and the slot provided in the lock housing for fastening the belt can serve to accommodate the angularly bent end portion of the locking tongue. As a rule this can be done without widening of the slot, since in the customary embodiment it is of a width more than suflicient for fastening of the belt strap in order to allow insertion of a pinch roller in said slot. The widening of the slot which is required to allow insertion of the pinch roller has, however, fulfilled its purpose with the insertion of such roller and thus constitutes a dead space in the prior art embodiment. Said space consequently is exploited in the buckle according to the present invention. The manufacture of the buckle is simplified since no projections need be provided in the lock housing, and the buckle is more convenient in use, since it is simpler to move the locking tongue into locking position; in the prior art buckle recited above it is necessary to guide the locking tongue relatively exactly straight into the lock housing in order that it may be brought into locking engagement.

For a better understanding the invention will be described in more detail in the following, reference being made to the accompanying drawing, in which FIG. 1 is a longitudinal sectional view of a buckle acv cording to the invention,

FIG. 2 is a plan view thereof, and

FIG. 3 is a fragmentary elevational view of the latch member as viewed along line HIIH in FIG. 1.

In the embodiment illustrated the lock housing includes a U-shaped element 10 in the web of which there is provided a relatively wide slot 11 for fastening of the belt strap 12 connected with the lock housing. Disposed in the slot is a non-rotatable but transversely displaceable pinch roller 13 which has been introduced in a known manner into the slot through a part thereof which is of a slightly greater length than the pinch roller, whereupon said pinch roller, the end surfaces of which are formed with grooves, has been passed onto the marginal portions of a part of the slot which is of smaller length than the pinch roller, receiving said marginal portions in said grooves. The pinch roller is retained in this part of the slot by means of a pair of bosses 14 provided in the limbs of U-shaped element 10. The distance between such limbs is bridged by a shaft 15 which is non-rotatably secured in the limbs, and pivotally mounted on said shaft are an operating lever 16 arranged between the limbs of element 1% and forming a cover over the web of such element (said operating lever can thus be considered as a part of the lock housing), and a U-shaped latch member 17 arranged beneath the operating, lever. A coil spring 18A is passed onto the shaft 15 and has one end attached to said shaft while it exerts a pressure on the Web of latch member 17 with its other end, tending to swing said member clockwise as viewed in FIG. 1, such swinging movement being limited by a projection 17' on the web of latch member 17, engaging the web of U-shaped element 10. Another coil spring 18B also passed onto shaft 15 and having one end attached to said shaft exerts a pressure on the operating lever 16, thus tending to swing said lever clockwise as viewed in FIG. 1. However, the swinging movement is limited by the lever being pressed with its free end against the web of element 19. The U-shaped latch member 17 can be swung, vhowever, counter-clockwise as viewed in FIG. 1 against the action of the spring 18a without intervention of the operating lever and without said lever partaking in the swinging movement, and it is also possible to swing the operating lever in the same direction against the action of spring 183 while the U-shaped latch member 17 is simultaneously carried along in the swinging movement by engagement betweensaid lever and shoulders 19 on the limbs of latch member 17. v

The buckle further includes a locking tongue 20 which is formed with a slot 21 for fastening of the belt strap 22 connected with said locking tongue and has an end portion 23 bent in of such a length as to be insertable in the slot 11 in the lock housing, and of such a height that the locking tongue does not go free betweenU-shaped latch member 17 and the Web of element 10' when it is attempted to insert the angularly bent end of the locking tongue in the lock housing and the'latch member is in the angular position defined by engagement between projection 17' and the web of U-shaped element 10. When it is so attempted to insert the locking'tongue the angularly bent end thereof, however, exerts a pressure on the limbs of latch member 17, and it is then possible to press these limbs out of the way against the action of the spring 18A while latch member 17 'is swung counter-clockwise, said limbs beingheld in an angular position suitable for engagement with the angularly bent end of locking tongue 29 by projection 17 when engaging web of U-shaped element 10. Thus, the locking tongue can be inserted .in the lock housing between the limbs a of latch member 17 and the web of the element 10 to snap into the slot 11 with its angularly bent end portion 3 23. When this end portion snaps into position latch member 17 under the action of spring 18A swings back to the position shown, and then the locking tongue is in locking position sinceits withdrawal from the lock housing is prevented by the mutual engagement between the angularly bent end portion 23 of the locking tongue and the boundary surface of the slot 11, and the locking tongue cannot bemoved out of this engagement by raising it fromthe web of the element 16, that is'by displacement transversely of the direction of insertion/withdrawal, as such raising is prevented by latch member 17 the limbs of which are situated close to the locking tongue in the operative position shown. The locking tongue can be released from the lock housing by positively swinging latch member 17 counter-clockwise as viewed in FIG. 1 againstthe action of spring 13A by pivotment of operating lever 16 counter-clockwise against the action of spring 183, that is by raising of the free end of the operating lever from the web of element 10. For limitation of the depth of insertion of the' locking tongue into the lock housing to that required to cause the locking tongue to engage, said locking tongue is formed with a narrower portion adjacent the angularly bentend and a wider portion adjacent the other end, shoulders 24 being formed between said two portions for restricting the depth of insertion by engagement with the limbs of the element 10. A hole 25 is provided in the locking tongue to permit suspension thereof when it is separated from the lock housing, such hole being connected withthe end of the locking tongue by a passage 26. When latch member 17 is in the operative position shown in FIG. 1, said passage receives projection 17. In such operative position, projection 17 preferably does not contact the web of element 10, the web of latch member 17 thus bearing on the locking tongue'on each side of said projection under the pressure exerted by said lock housing and said angularly bent end portion of said locking tongue forming abutment surfaces to prevent by mutual engagement the withdrawal of said locking tongue from the locking position in said lock housing, a latch having a pivotal mounting in said lock housing for movement to and from a latching position and having a lower surface adapted in the latching position in cooperation with said web portion of said lock housing to prevent the abutment surfaces from being moved out of mutual engagement, a projection formed on said latch and accommodated in said opening in said locking tongue inserted in said locking position, spring means biasing said latch into the latching position, said projection having a'portion which is farthest from said pivotal mounting located a distance from said mounting greater than the shortest distance between said Web and said mounting so as to keep said latch in an angular position suitable for moving said latch out of the way against the action of said spring means when said locking tongue is inserted into said lock housing, and an operating member for moving said latch out of latching position against the action of the spring bias.

2. A buckle in accordance with claim 1, in which said opening in said locking tongue is formed with a through passage therefrom opening to an edge and adapted to receive said projection.

3. A buckle in accordance with claim 2, inwhich the length of the portion of said projection extending below the lowest surface of said latch adjacent said locking tongue is smaller than the thickness of said locking tongue in order that said latch, when said locking tongue is inserted in said lock housing and said projection is accommodated in the opening of said locking tongue, may be applied against the locking tongue on either side of said projection.

References Cited by the Examiner V UNITED STATES PATENTS 854,196

r DONLEY J. STOCKING, Primary Examiner. 

1. A BUCKLE FOR A SAFETY BELT COMPRISING A LOCK HOUSING HAVING A WEB PORTION AND A SLOT THEREIN, MEANS FOR ATTACHING A BELT TO SAID LOCK HOUSING, A LOCKING TONGUE INSERTABLE IN SAID HOUSING TO A LOCKING POSITION THEREIN AND HAVING MEANS FOR ATTACHING A BELT THERETO, SAID LOCKING TONGUE HAVING AN OPENING THEREIN AND AN ANGULARLY BENT END PORTION, A BOUNDARY SURFACE OF THE SLOT IN SAID LOCK HOUSING AND SAID ANGULARLY BENT END PORTION OF SAID LOCKING TONGUE FORMING ABUTMENT SURFACES TO PREVENT BY MUTUAL ENGAGEMENT THE WITHDRAWAL OF SAID LOCKING TONGUE FROM THE LOCKING POSITION IN SAID LOCK HOUSING, A LATCH HAVING A PIVOTAL MOUNTING IN SAID LOCK HOUSING FOR MOVEMENT TO AND FROM A LATCHING POSITION AND HAVING A LOWER SURFACE ADAPTED IN THE LATCHING POSITION IN COOPERATION WITH SAID WEB PORTION OF SAID LOCK HOUSING TO PREVENT THE ABUTMENT SURFACES FROM BEING MOVED OUT OF MUTUAL ENGAGEMENT, A PROJECTION FORMED ON SAID LATCH AND ACCOMMODATED IN SAID OPENING IN SAID 